Paratesticular fibrous pseudotumours are rare intrascrotal lesions, most frequently affecting the testicular tunics. They are benign in nature; however, their pathogenesis is not completely understood. Presenting features are similar to testicular malignancy, which may result in unnecessary radical surgery. It has been suggested that additional diagnostic imaging combined with frozen section analysis may help prevent orchiectomy in these patients. We describe a case of paratesticular fibrous pseudotumour in a 40-year-old male treated with testicle-sparing surgery aided by intraoperative frozen section analysis.
IntroductionParatesticular fibrous pseudotumours (PFPs) are rare, benign lesions believed to result from fibroinflammatory processes. They present most commonly as painless scrotal masses and occur as single or disseminated nodules. They frequently involve the tunica vaginalis, with rarer cases arising from the tunica albuginea, epididymis and spermatic cord. [1][2][3][4][5][6] Peak incidence occurs in the third decade of life, but reports exist in all age groups.7 Although patients may report a history of testicular trauma, infection or hydrocele, the similarity in presentation to malignancy often results in radical surgery with diagnosis made on the resected specimen.
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Case report
Clinical findingsA 40-year-old man presented with a history of right hemiscrotal fullness and palpable nodules. The nodules grew tender over time. Physical examination revealed several small, right-sided scrotal lesions. Interpretation of scrotal ultrasound described microlithiases, and an enlarged, lobulated and echogenic right epididymis. There was one small epididymal cyst measuring 3 mm. The patient was booked for surgical exploration, which revealed solid nodules lining much of the tunica vaginalis. A specimen sent for frozen section revealed heavily collagenized, hypocellular tissue with chronic inflammatory infiltrate. No malignancy was identified. About one-third of the tunica vaginalis was removed and the remainder of the testicle was spared (Fig. 1).
Pathological findingsGross examination revealed tan-grey tissue measuring 7.0 × 3.5 × 1.2 cm, with a roughened surface and opposing smooth, pearly grey tunica/mesothelial surface containing many polypoid projections (Fig. 2). Nodules measured up to 1.1 cm in greatest dimension. Microscopic examination revealed hypocellular tissue composed of thick collagen bundles with areas of hyalinization, thick and thin walled vessels and a background mixed inflammatory infiltrate consisting primarily of plasma cells with admixed lymphocytes and occasional mast cells (Fig. 3). There were occasional lymphoid aggregates and plump fibroblasts. Several vessels demonstrated concentric perivascular fibrosis. Immunohistochemistry revealed monokeratin-and vimentinpositive cells between the collagen bands. These cells also stained weakly for D2-40 and CD34, consistent with fibroblasts/myofibroblasts. LCA stain highlighted the background inflammatory cells and lymphoid aggregates. V...